Adjust runtime error handlers, convert to static properties

Signed-off-by: Sean Williams <72675818+sean-r-williams@users.noreply.github.com>

ast/builtins.go

@@ -1718,11 +1718,11 @@ var JSONMarshalWithOptions = &Builtin{
 			types.Named("opts", types.NewAny(
 				types.NewNull(),
 				types.NewObject(
-					nil,
-					types.NewDynamicProperty(
-						types.S,
-						types.A,
-					),
+					[]*types.StaticProperty{
+						types.NewStaticProperty("indent", types.NewAny(types.S, types.NewNull())),
+						types.NewStaticProperty("prefix", types.NewAny(types.S, types.NewNull())),
+					},
+					types.NewDynamicProperty(types.S, types.A),
 				),
 			)).Description("encoding options - accepts keys `prefix` (string to prefix lines with, default empty string) and `indent` (string to indent with, default `\\t`)"),
 		),

builtin_metadata.json

@@ -10389,7 +10389,7 @@
       {
         "description": "encoding options - accepts keys `prefix` (string to prefix lines with, default empty string) and `indent` (string to indent with, default `\\t`)",
         "name": "opts",
-        "type": "any\u003cnull, object[string: any]\u003e"
+        "type": "any\u003cnull, object\u003cindent: any\u003cnull, string\u003e, prefix: any\u003cnull, string\u003e\u003e[string: any]\u003e"
       }
     ],
     "available": [

capabilities.json

@@ -2212,6 +2212,36 @@
                     "type": "any"
                   }
                 },
+                "static": [
+                  {
+                    "key": "indent",
+                    "value": {
+                      "of": [
+                        {
+                          "type": "null"
+                        },
+                        {
+                          "type": "string"
+                        }
+                      ],
+                      "type": "any"
+                    }
+                  },
+                  {
+                    "key": "prefix",
+                    "value": {
+                      "of": [
+                        {
+                          "type": "null"
+                        },
+                        {
+                          "type": "string"
+                        }
+                      ],
+                      "type": "any"
+                    }
+                  }
+                ],
                 "type": "object"
               }
             ],

topdown/encoding.go

@@ -58,9 +58,9 @@ func builtinJSONMarshalWithOpts(_ BuiltinContext, operands []*ast.Term, iter fun
 
 			val := marshalOpts.Get(k)
 
-			key, err := builtins.StringOperand(k.Value, 2)
+			key, err := builtins.StringOperand(k.Value, idx)
 			if err != nil {
-				return err
+				return builtins.NewOperandErr(2, "failed to stringify key %v at index %d: %v", k, idx, err)
 			}
 
 			switch key {
@@ -72,7 +72,7 @@ func builtinJSONMarshalWithOpts(_ BuiltinContext, operands []*ast.Term, iter fun
 				default:
 					prefixOpt, err := builtins.StringOperand(val.Value, idx)
 					if err != nil {
-						return builtins.NewOperandErr(2, "key %s contained invalid type: %v", key, err)
+						return builtins.NewOperandErr(2, "key %s failed cast to string: %v", key, err)
 					}
 					prefixWith = string(prefixOpt)
 				}
@@ -84,7 +84,7 @@ func builtinJSONMarshalWithOpts(_ BuiltinContext, operands []*ast.Term, iter fun
 				default:
 					indentOpt, err := builtins.StringOperand(val.Value, idx)
 					if err != nil {
-						return builtins.NewOperandErr(2, "key %s contained invalid type: %v", key, err)
+						return builtins.NewOperandErr(2, "key %s failed cast to string: %v", key, err)
 
 					}
 					indentWith = string(indentOpt)